Myeloid cell-targeted miR-146a mimic inhibits NF-κB-driven inflammation and leukemia progression in vivo.

NF-κB is a key regulator of inflammation and cancer progression, with an important role in leukemogenesis. Despite its therapeutic potential, targeting NF-κB using pharmacologic inhibitors has proven challenging. Here, we describe a myeloid cell-selective NF-κB inhibitor using an miR-146a mimic oligonucleotide conjugated to a scavenger receptor/Toll-like receptor 9 agonist (C-miR146a). Unlike an unconjugated miR146a, C-miR146a was rapidly internalized and delivered to the cytoplasm of target myeloid cells and leukemic cells. C-miR146a reduced expression of classic miR-146a targets (IRAK1 and TRAF6), thereby blocking activation of NF-κB in target cells. IV injections of C-miR146a mimic to miR-146a-deficient mice prevented excessive NF-κB activation in myeloid cells, and thus alleviated myeloproliferation and mice hypersensitivity to bacterial challenge. Importantly, C-miR146a showed efficacy in dampening severe inflammation in clinically relevant models of chimeric antigen receptor (CAR) T-cell-induced cytokine release syndrome. Systemic administration of C-miR146a oligonucleotide alleviated human monocyte-dependent release of IL-1 and IL-6 in a xenotransplanted B-cell lymphoma model without affecting CD19-specific CAR T-cell antitumor activity. Beyond anti-inflammatory functions, miR-146a is a known tumor suppressor commonly deleted or expressed at reduced levels in human myeloid leukemia. Using The Cancer Genome Atlas acute myeloid leukemia data set, we found an inverse correlation of miR-146a levels with NF-κB-related genes and with patient survival. Correspondingly, C-miR146a induced cytotoxic effects in human MDSL, HL-60, and MV4-11 leukemia cells in vitro. The repeated IV administration of C-miR146a inhibited expression of NF-κB target genes and thereby thwarted progression of disseminated HL-60 leukemia. Our results show the potential of using myeloid cell-targeted miR-146a mimics for the treatment of inflammatory and myeloproliferative disorders.

Using Pharmacogenomic Databases for Discovering Patient-Target Genes and Small Molecule Candidates to Cancer Therapy.

With multiple omics strategies being applied to several cancer genomics projects, researchers have the opportunity to develop a rational planning of targeted cancer therapy. The investigation of such numerous and diverse pharmacogenomic datasets is a complex task. It requires biological knowledge and skills on a set of tools to accurately predict signaling network and clinical outcomes. Herein, we describe Web-based in silico approaches user friendly for exploring integrative studies on cancer biology and pharmacogenomics. We briefly explain how to submit a query to cancer genome databases to predict which genes are significantly altered across several types of cancers using CBioPortal. Moreover, we describe how to identify clinically available drugs and potential small molecules for gene targeting using CellMiner. We also show how to generate a gene signature and compare gene expression profiles to investigate the complex biology behind drug response using Connectivity Map. Furthermore, we discuss on-going challenges, limitations and new directions to integrate molecular, biological and epidemiological information from oncogenomics platforms to create hypothesis-driven projects. Finally, we discuss the use of Patient-Derived Xenografts models (PDXs) for drug profiling in vivo assay. These platforms and approaches are a rational way to predict patient-targeted therapy response and to develop clinically relevant small molecules drugs.

Dermcidin exerts its oncogenic effects in breast cancer via modulation of ERBB signaling.

BACKGROUND: We previously identified dermicidin (DCD), which encodes a growth and survival factor, as a gene amplified and overexpressed in a subset of breast tumors. Patients with DCD-positive breast cancer have worse prognostic features. We therefore searched for specific molecular signatures in DCD-positive breast carcinomas from patients and representative cell lines. METHODS: DCD expression was evaluated by qRT-PCR, immunohistochemical and immunoblot assays in normal and neoplastic tissues and cell lines. To investigate the role of DCD in breast tumorigenesis, we analyzed the consequences of its downregulation in human breast cancer cell lines using three specific shRNA lentiviral vectors. Genes up- and down-regulated by DCD were identified using Affymetrix microarray and analyzed by MetaCore Platform. RESULTS: We identified DCD splice variant (DCD-SV) that is co-expressed with DCD in primary invasive breast carcinomas and in other tissue types and cell lines. DCD expression in breast tumors from patients with clinical follow up data correlated with high histological grade, HER2 amplification and luminal subtype. We found that loss of DCD expression led to reduced cell proliferation, resistance to apoptosis, and suppressed tumorigenesis in immunodeficient mice. Network analysis of gene expression data revealed perturbed ERBB signaling following DCD shRNA expression including changes in the expression of ERBB receptors and their ligands. CONCLUSIONS: These findings imply that DCD promotes breast tumorigenesis via modulation of ERBB signaling pathways. As ERBB signaling is also important for neural survival, HER2+ breast tumors may highjack DCD's neural survival-promoting functions to promote tumorigenesis.

Cell death-associated molecular-pattern molecules: inflammatory signaling and control.

Apoptosis, necroptosis, and pyroptosis are different cellular death programs characterized in organs and tissues as consequence of microbes infection, cell stress, injury, and chemotherapeutics exposure. Dying and death cells release a variety of self-proteins and bioactive chemicals originated from cytosol, nucleus, endoplasmic reticulum, and mitochondria. These endogenous factors are named cell death-associated molecular-pattern (CDAMP), damage-associated molecular-pattern (DAMP) molecules, and alarmins. Some of them cooperate or act as important initial or delayed inflammatory mediators upon binding to diverse membrane and cytosolic receptors coupled to signaling pathways for the activation of the inflammasome platforms and NF-κB multiprotein complexes. Current studies show that the nonprotein thiols and thiol-regulating enzymes as well as highly diffusible prooxidant reactive oxygen and nitrogen species released together in extracellular inflammatory milieu play essential role in controlling pro- and anti-inflammatory activities of CDAMP/DAMP and alarmins. Here, we provide an overview of these emerging concepts and mechanisms of triggering and maintenance of tissue inflammation under massive death of cells.

Bortezomib (PS-341) treatment decreases inflammation and partially rescues the expression of the dystrophin-glycoprotein complex in GRMD dogs.

Golden retriever muscular dystrophy (GRMD) is a genetic myopathy corresponding to Duchenne muscular dystrophy (DMD) in humans. Muscle atrophy is known to be associated with degradation of the dystrophin-glycoprotein complex (DGC) via the ubiquitin-proteasome pathway. In the present study, we investigated the effect of bortezomib treatment on the muscle fibers of GRMD dogs. Five GRMD dogs were examined; two were treated (TD- Treated dogs) with the proteasome inhibitor bortezomib, and three were control dogs (CD). Dogs were treated with bortezomib using the same treatment regimen used for multiple myeloma. Pharmacodynamics were evaluated by measuring the inhibition of 20S proteasome activity in whole blood after treatment and comparing it to that in CD. We performed immunohistochemical studies on muscle biopsy specimens to evaluate the rescue of dystrophin and dystrophin-associated proteins in the muscles of GRMD dogs treated with bortezomib. Skeletal tissue from TD had lower levels of connective tissue deposition and inflammatory cell infiltration than CD as determined by histology, collagen morphometry and ultrastructural analysis. The CD showed higher expression of phospho-NFκB and TGF-ß1, suggesting a more pronounced activation of anti-apoptotic factors and inflammatory molecules and greater connective tissue deposition, respectively. Immunohistochemical analysis demonstrated that dystrophin was not present in the sarcoplasmic membrane of either group. However, bortezomib-TD showed higher expression of α- and ß-dystroglycan, indicating an improved disease histopathology phenotype. Significant inhibition of 20S proteasome activity was observed 1 hour after bortezomib administration in the last cycle when the dose was higher. Proteasome inhibitors may thus improve the appearance of GRMD muscle fibers, lessen connective tissue deposition and reduce the infiltration of inflammatory cells. In addition, proteasome inhibitors may rescue some dystrophin-associated proteins in the muscle fiber membrane.

Identification of a metallopeptidase with TOP-like activity in Paracoccidioides brasiliensis, with increased expression in a virulent strain.

Paracoccidioidomycosis (PCM), caused by the pathogenic fungus Paracoccidioides brasiliensis, is a systemic mycosis with severe acute and chronic forms. The pathology of PCM is not completely understood, and the role of proteases in the infection is not clearly defined. In this report, we describe a metallopeptidase activity in P. brasiliensis total and cytosolic protein extracts similar to that of mammalian thimet oligopeptidase (TOP). The analogous enzyme was suggested by analysis of P. brasiliensis genome databank and by hydrolytic activity of the FRET peptide Abz-GFSPFRQ-EDDnp which was completely inhibited by o-phenanthrolin and significantly inhibited by the TOP inhibitor, JA-2. This activity was also partially inhibited by IgG purified from patients with PCM, but not from normal individuals. As shown by high-performance liquid chromatography (HPLC), the hydrolysis of bradykinin had the same pattern as that of mammalian TOP, and anti-mammalian TOP antibodies significantly inhibited fungal cytosolic peptidase activity. Moreover, anti-mammalian TOP antibodies recognized a component of 80 kDa on fungal cytosol. A P. brasiliensis virulent isolate showed higher gene expression and TOP-like peptidase activity than a non-virulent strain. The release of enzyme following fungal lysis would be consistent with host antibody production and may have a role in the pathogenesis, inflammation and further development of the mycosis.